Torque sensing coupling with contact carrying spacer element



April 14, 1964 c. MOYLES TORQUE SENSING COUPLING WITH CONTACT CARRYING SPACER ELEMENT Filed Oct. 24, 1962 3 56 4 4 -r// m INVENTOR.

CHARLES Leo MoYLEs BY 2 9 ATTORNEYS United States Patent Ofitice 3,129,300 Patented Apr. 14, 1964 3,12%300 TORQUE SENSENG CUUPLING WITH CONTACT CARRYING SPACER ELEMENT Charles Leo Moyles, Royal Oak, Mich, assignor to Champion Spark Plug Company, Toledo, Ohio, a corporation of Delaware Filed Get. 24, 1962, Ser. No. 232,806 3 Claims. (Cl. 20061.46)

The present invention relates to couplings for connecting driving and driven rotatable shafts; and more particularly to couplings which will sense torque overload and provide an electrical signal for shutting down the prime mover of the driving shaft.

An object of the present invention is the provision of a new and improved torque sensing coupling of the type having electrical contacts which will be directly operated by an overload, and which is simple in design, rugged in construction, and efiicient in operation.

A further object of the invention is the provision of a new and improved torque sensing coupling of the above described type which will transmit the rotary motion of the driving shaft to the driven shaft with extreme fidelity and without imparting any fluctuations or oscillations in speed until such time as an overload is sensed and the prime mover is shut down.

The invention resides in certain constructions and combinations and arrangements of parts; and further objects and advantages of the invention will be apparent to those skilled in the art to which it relates from the following description of a preferred embodiment described with reference to the accompanying drawings, forming a part of this specification, and in which:

FIG. 1 is a side elevational view of a coupling and its attendant driving and driven shafts, in which the prime mover and associated electrical circuitry is shown schematically;

FIG. 2 is a cross sectional View taken approximately on the line 2-2 of FIG. 1;

PEG. 3 is a cross sectional view taken approximately on the line 3-3 of FIG. 1; and

FIG. 4 is a fragmentary, cross-sectional view taken approximately on the line 4-4- of FIG. 3.

Generally speaking, the present invention comprises a torque sensing device having first and second annular collars adapted to be secured to aligned driving and driven shafts-each of the collars having axially extending projecting portions which laterally overlie each other, and which include generally parallel spaced apart side abutment surfaces which face each other, and which extend along planes generally parallel to said shafts. The coupling further includes a cross-shaped spacer member having legs extending between the side abutment surfaces. The spacer member carries a first electrical contact positioned to face a side abutment surface of one of the collars, and a second electrical contact is supported by the adjacent side abutment surface in a position to be contacted by the first contact. The torque sensing device further includes spring means resiliently biasing the side abutment surfaces a predetermined distance apart to oppose the driving torque and norm-ally provide clearance between the spacer member and one of the abutment surfaces. The contacts are caused to have open and closed conditions-one of which occurs when the above described clearance is provided by the spring means, and the other of which contact condition occurs when the spring means yields to cause the clearance to be taken up between the spacer member and the abutment surface.

The torque sensing coupling of the present invention generally comprises a driving collar and a driven collar 12 which are respectively positioned on the adjacent ends of a driving shaft 14 and an aligned driven shaft 16 respectively.

The driving shaft 14 and the driving coupling 10 have key ways 18 and 20 therein (FIG. 2) which are aligned to receive a key 22 that is held in place by means of a set screw 24. -In like fashion, the driven shaft 16 and driven coupling 12 have key ways 26 and 28, respectively, aligned to receive a key 3i} held in place by means of a set screw 32. A cross-shaped member 34 (see also FIG. 3) is positioned between the driving and driven collars 1i) and 12. The member 34 has legs 36, 38, 40 and 42, which are positioned between adjacent ones of quadrant spaces 44, 46, 4S and 5h. The quadrant space 44 is between the legs 36 and 38; the quadrant space 46 is between the legs 38 and 40; the quadrant space 48 is between the legs iii' and 42; and the quadrant space 50 is between the legs 42 and 36. The opposite side surfaces of each of the legs of the cross shaped member 34 are generally parallel and extend in the same direction as the shafts l4 and 16 to provide abutment surfaces for reasons which will later be apparent.

The driving collar Iii is provided with a pair of diametrically opposite quadrant segments 52 and 54 which project axially into the quadrant spaces 50 and 46 respectively, and substantially fill the quadrant spaces but at the same time provide a slight clearance between the abutment surfaces. In like fashion, the driven collar 12 is also provided with a pair of quadrant segments 56 and 58 which project axially into the quadrant spaces 44 and 4d, substantially filling the respective spaces and at the same time providing a slight clearance between the abutment surfaces.

Upon rotation of the driving shaft 14, an abutment surface 65} of the driving quadrant segment 52 abuts the leg 36 of the crossmember 34 while an abutment surface 62 of the driving quadrant segment 54 abuts the leg 40 to cause a rotation of the cross member 34. Rotation of the cross member 34 is transmitted to the driven quadrant segments 56 and 58- through coil springs 64 and 66 which are positioned between the quad-rants 56' and 58 and the legs 36 and 4h, respectively, of the cross shaped member =34. The springs 64 and 66 are positioned in cross openings 68 and 70, respectively, in the quadrant segments '56 and 58, and are held in place by means of set screws 72 and 74 respectively. When the set screws 72 and 74 are suitably positioned, the springs 64 and 66 are compressed into engagement with the abutment surfaces 76 and 78 of the legs 36 and 4t), respectively, to hold the abutment surfaces 76' and 78 out of engagement with the quadrant segments 56 and 58 until such time as the springs '64 and 6d are overloaded.

When the springs 64 and 66 are overloaded, relative movement occurs between the legs 36 and 40, and the quadrant segments 52, 54, 56 and 58. This relative movement is detected by a pair of contacts, one of which is positioned on one of the legs of the cross-shaped member 34 and the other of which is positioned on one of the quadrants 52-58. In the embodiment shown in the drawings, the leg 36 of the cross-shaped member 34 is provided with a threaded opening 8t) and a yieldable contact 82 is positioned therein. The contact 32 comprises a headed contact button 84 which is received in and slidably projects out of the central opening 86 of a generally tubular adjustment member 88. The opening 86 is enlarged or counterbored in the area which receives the head of the button member, and the small end of the button member projects out of the tubular member 88 and is held in place by means of a screw 90. A spring 92 is positioned between the head of the button 84 and the bottom of the counterbore to hold the screw 90 against the end of the adjustment member 88. The adjustment member 88 is threaded into the opening 80 and has a suitable screw driver slot 94 by means of which its position is adjusted lengthwise of the opening 88. Opposite the contact button 84, an opening 96 is provided in the quadrant segment 56, and an electrical contact 98 is adjustably positioned in the opening 96. The contact 88 is threaded and so its position is also adjustable in the opening 96. By suitably adjusting the contact 98, the contacts 84 and 98 are held out of engagement with each other until the coil springs 64 and 66 are overloadedat which time the cross-shaped member 34 moves to bring the contact 84 into engagement with the contact 98. The coil spring 92 provides a yielding mechanism which prevents damage to the contacts when they come together.

The electrical circuit for the contact 84 is completed by means of a wire 1%, see FIG. 4, whose other end is connected to a terminal strip 182, which is positioned on the outer end of the leg 36 of the cross-shaped member 34. The terminal strip 182 in turn is connected to an electrically conductive means comprising a slip ring 104, best seen in FIG. 1, by means of another wire we. Closing of the contacts 84 and 98 operates a relay tea which in turn deenergizes the controls of the prime mover 110 for the driving coupling 10. It is intended that the structure shown will be used in the driving of a conveyor on which apparatus must be positioned Within a thousandth of an inch, so that there can be no fluctuation in the rate at which the prime mover 110 drives the conveyor relative to an independently driven conveyor loading structure. It will be seen from the structure so far described that the springs 64 and 66 hold a constant clearance between the abutment surfaces 76 and 78 and the quadrant segments 56 and 58, respectively, until such times as the springs are overloaded, so there is no relative movement until such time as the springs are overloaded. When an overload develops, however, and a slight relative rotation occurs between the driving and driven structures to put the conveyor out of phase with the independently driven conveyor loading structure, the relay 108 is operated and the prime mover 110 is shut down.

During operation it will sometimes be necessary to slow down the prime mover 110 at a rate faster than the rate at which the conveyor will slow down. Inasmuch as there is an appreciable amount of inertia in the driven structure, a pair of springs, one of which is in the quadrant segment 52 and is designated 112, and the other of which 114 is in the segment 54, resist overtaking of the driving quadrants 52 and 54 by the cross-shaped member 34. These springs, along with thereceiving bores and set screws, are identical to those previously described for springs 64 and 66, and so will not further be described.

While the contacts 84 and 98 have been described 'as being normally open contacts, it will readily be apparent that the contact 84 can have its position reversed, and that the contact 98 can be positioned in the quadrant segment 56. In this case, the contacts 84 and 98 may be normally closed, and will be opened upon compression of the coil springs 64 and 66 as occurs during an overload. Upon deenergizing of the circuits operated by the contacts, therefore, a similar shutdown of the prime mover can be had, or any other control function may be initiated which it is desired to provide.

While the invention has been described in considerable detail, it is not to be limited to the particular embodiment shown and described; and it is intended to cover hereby all novel adaptations, modifications and arrangements thereof which come within the practice of those skilled in the art to which the invention relates.

What I claim is:

l. A torque sensing device for positioning between axially aligned rotatable driving and driven shafts, said torque sensing device comprising: first and second annular collars'adapted to be secured to said driving and driven shafts respectively, said collars having axially projecting portions which overlie each other and which include generally parallel spaced apart side abutment surfaces which face each other and which extend along planes generally parallel to said shafts, an electrically non-conductive spacer member facing one of said side abutment surfaces, ment surfaces, a first electrical contact supported by said spacer member facing one of said side abtument surfaces, a second electrical contact supported by said one of said side abutment surfaces in a position to be contacted by said first contact, spring means resiliently biasing said abutment surfaces a predetermined distance apart to op pose driving torque and normally provide clearance between said spacer member and one of said abutment sur faces, said contacts having'open and closed positions and being biased to assume one of the two positions when said clearance is provided by said spring means, but movable to the other position upon predetermined yielding of said spring means, and electrically conductive means for sensing the position of said contacts, whereby transmitted torque above a predetermined value overcomes said spring means and actuates said contacts.

2. A torque sensing device for positioning between axially aligned rotatable driving and driven shafts, said torque sensing device comprising: driving and driven annular collars adapted to be secured to said driving and driven shafts respectively, a cross-shaped member positioned axially between said collars, said cross-shaped member having four legs with generally parallel side surfaces which extend in axial directions and which define generally ninety degree quadrant spaces, said driving collar having a pair of quadrant segments which project in an axial direction into diametrically opposite quadrant spaces to provide side abutment surfaces spaced apart from adjacent side surfaces of said cross-shaped member, said driven collar having a pair of quadrant segments which project in an axial direction into the other two quadrant spaces, said latter quadrant segments also providing side abutment surfaces spaced apart from adjacent side surfaces of adjacent legs of said cross-shaped member, spring means biasing said abutment surfaces of said cross-shaped member and said driven member apart, and a pair of electrical contacts, respective members of which are positioned between said cross-shaped member and one of said quadrant segments for abutment with each other, said contacts having open and closed positions, and being biased to assume one of the two positions when said spring means hold said abutment surfaces apart, but movable to the other position when suflicient torque is transmitted to overcome said spring means and move said abutment surfaces together.

3. The torque sensing device of claim '2 wherein one contact is electrically connected to one of said collar members, and the other contact is electrically connected to a slip ring mounted on and electrically insulated from one of said collar members.

No references cited.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3 1295300 Apr-i1 14-, 1964 corrected below.

Column I lines 14 and 15, strike out- -"fac-in ones of said side abutment surfaces ment surfaces- 3.1 an-d insert instead loosely secured between said side-abutment surfaces, same column 4,, line 16, for -"'-ab=tument" read abutment Signed and sealed this 11th day of August 1964.

(SEAL) Attest:

ERNEST w.- SWIDER I EDWARD J. BRENNER Altesting Officer. Commissioner of Patents UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,129,300 April 14,- 1-964 corrected below.

Column l lines 14 and 15, strike out 'f-ac-in-g one; of said side abutment surfaces, ment surfaces -an-d-i-nsert instead loosely secured between said s-id e-abutment surfaces same column 4, line 16, for ab=tu me-n t read abutment Signed and sealed this 11th day of August 1964.

, (SEAL) Attest:

ER NEST w. SWIDER EDWARD J. BRENNER Attesting Officer Commissioner of Patents 

1. A TORQUE SENSING DEVICE FOR POSITIONING BETWEEN AXIALLY ALIGNED ROTATABLE DRIVING AND DRIVEN SHAFTS, SAID TORQUE SENSING DEVICE COMPRISING: FIRST AND SECOND ANNULAR COLLAR ADAPTED TO BE SECURED TO SAID DRIVING AND DRIVEN SHAFTS RESPECTIVELY, SAID COLLARS HAVING AXIALLY PROJECTING PORTIONS WHICH OVERLIE EACH OTHER AND WHICH INCLUDE GENERALLY PARALLEL SPACED APART SIDE ABUTMENT SURFACES WHICH FACE EACH OTHER AND WHICH EXTEND ALONG PLANES GENERALLY PARALLEL TO SAID SHAFTS, AN ELECTRICALLY NON-CONDUCTIVE SPACER MEMBER LOOSELY SECURED BETWEEN SAID SIDE ABUTMENT SURFACES, A FIRST ELECTRICAL CONTACT SUPPORTED BY SAID SPACER MEMBER FACING ONE OF SAID SIDE ABUTMENT SURFACES, A SECOND ELECTRICAL CONTACT SUPPORTED BY SAID ONE OF SAID SIDE ABUTMENT SURFACES IN A POSITION TO BE CONTACTED BY SAID FIRST CONTACT, SPRING MEANS RESILIENTLY BIASING SAID ABUTMENT SURFACES A PREDETERMINED DISTANCE APART TO OPPOSE DRIVING TORQUE AND NORMALLY PROVIDE CLEARANCE BE- 